https://indesignsecrets.com/tip-week-setting-exact-space-objects.php

This tutorial shows a way to expand the align and distribute tool. I want to space 9 lines by exactly 10mm from their centers but the dialog option doesn't exist anymore. How do I find it?

Are you expecting a feature of InDesign software to exist in Inkscape?

This tut isn´t meant for Inkscape right?

But here you go:

Open Document Properties

go->Grids - click NEW

Grid Units: mm

Spacing X: 10,0

SpacingY: 10,0

Major grid line every: 1

Enable snapping to Grids

Draw one path - duplicate - click and drag as much you need.